This invention relates to the formation of miniaturized shaped components such as components for microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS).
Current technology for producing MEMS and NEMS devices is based mainly on silicon microfabrication techniques. Silicon, however, has relatively poor mechanical properties which rendered forming techniques difficult. New materials and fabrication techniques are need to produce micro components with greater reliability.
Nanostructured materials exhibit exceptional strength and fatigue properties, rendering them good candidates for high performance micro components. Fabrication is difficult, however, because conventional machining techniques available for larger components do not readily scale down for use with micro components.
Matsumoto et al. U.S. Pat. No. 5,324,368 disclosed a method for forming components from amorphous materials relying on fluid pressure as a deformation force and a furnace or oil bath to heat the material to be deformed.
Saotome et al., xe2x80x9cSuperplastic Extrusion of Microgear Shaft of 10 um in Module,xe2x80x9d Microsystem Technologies 6 (2000) 126-129, disclosed microextrusion of Al-78Zn, observing cavities, voiding, and surface roughness at higher strain rates.
There is a need for an improved method for making micro scale components including MEMS and NEMS components.
Briefly, therefore, the invention is directed to a method for forming a miniaturized shaped component. Bulk superplastic material is contacted with a flat rotating surface of a rotating tool to frictionally heat the bulk superplastic material with the bulk superplastic material positioned between the flat rotating surface of the tool and a microfabricated tool die. The bulk superplastic material is forced into the microfabricated die once the bulk superplastic material is heated to a temperature between a glass transition temperature and a crystallization temperature of the bulk superplastic material by moving the tool and die closer to each other with the bulk superplastic material therebetween to produce a miniaturized shaped component conforming to a shape of the microfabricated tool die.
The invention is also directed to a method for extruding a miniaturized cross-section component involving contacting bulk superplastic material with a flat rotating surface of a rotating tool to frictionally heat the bulk superplastic material with the bulk superplastic material positioned between the flat rotating surface of the tool and a microfabricated extrusion die. The bulk superplastic material is forced into the microfabricated extrusion die once the bulk superplastic material is heated to a superplastic temperature range to produce an extrusion with a miniaturized cross section.
In another aspect the invention is a method for forming a component of miniaturized cross section in which the bulk superplastic material is heated by contacting an encapsulating material which encapsulates the bulk superplastic material with a flat rotating surface of a rotating tool to frictionally heat the encapsulating material. This heats the bulk superplastic material, with the bulk superplastic material and encapsulating material positioned between the flat rotating surface of the tool and a microfabricated die. The bulk superplastic material is forced into the microfabricated die once the bulk superplastic material is heated to a temperature between a glass transition temperature and a crystallization temperature of the bulk superplastic material. This is achieved by moving the tool and die closer to each other with the bulk superplastic material therebetween and with the encapsulating material transmitting pressure from the tool to the bulk superplastic material to produce a shaped component of miniaturized cross section conforming to a shape of the microfabricated die.
Other objects and features will be in part apparent and in part pointed out hereinafter.